Reclosable package



April 15, 1969 Filed March 27. 1967 D. D. MILLER ET AL RECLOSABLEPACKAGE {fig INVENTORS 20064 0522 Na. 1. .5 A

mamas/Va mmeo 601v F/cmswo .B. fiv/ uwv April 15, 1969 MILLER ET AL3,438,483

RECLOSABLE PACKAGE Filed March 2'7. 1967 I N V EN TORS D0064 05D. MIL1.:12

mam: Awmea 146 660V United States Patent 3,438,483 RECLOSABLE PACKAGEDouglas D. Miller, Marietta, Thomas Howard Hogan,

Atlanta, and Richard B. Inman, Dunwoody, (221., as-

signors to Scientific-Atlanta, Inc., Atlanta, Ga., a corporation ofGeorgia Filed Mar. 27, 1967, Ser. No. 626,168

Int. Cl. B65d 83/00, 5/64, 43/00, 17/00, 5/54, 5/70 US. Cl. 20656 7Claims ABSTRACT OF THE DISCLOSURE A reclosable lid for a receptaclewhich is a rigid or semi-rigid plastic cup or tray having a bottom, asidewall and a flange extending laterally outwardly from the upper edgeof the sidewall. The lid is flat and is composed of a laminate of metalfoil and paper or cardboard. The lid extends beyond the flange of thecup or tray at two or more places spaced around the cup and generally atone side thereof. The lid is sealed to the flange of the cup. On openingthe cup, the lid is not entirely removed but a peripheral portion of itis left sealed to the flange on the side opposite the extendingportions. Indicia on the lid indicate this peripheral portion. When thelid is pressed back against the flange, the consumer folds the lid underthe flange at the places where the lid extends beyond the flange. Thefolded under portions are crimped to the underside of the flange andhold the lid in place.

The present invention relates to a container and more particularly to acontainer having a closure sealed to a container body which can beremoved and then replaced to reclose the container.

The type of container body with which the invention is particularlyconcerned is a rigid or semi-rigid plastic cup or tray having a bottom,a sidewall and a flange extending laterally outwardly from the upperedge of the sidewall. The cup is filled with a product, for examplesliced luncheon meat, and closed with a substantially flat lid whichextends over the flange and is sealed to it.

From the consumers point of view, containers of this type represent asubstantial improvement over flexible film wrappings and plastic bagswhich have been used widely to package sliced cheese, sliced luncheonmeat and a wide variety of other products. The principal advantages arethat the rigid or semi-rigid cup functions as a permanent receptacle fora product. The consumer can open it, remove part of the contents andthen store the remainder of the contents in the cup for later use. Inthe case of a plastic bag, it is necessary to remove all of the product,in some cases, in order to gain access to a part, and then to replacethe unused portion, and both removal and replacement are awkward. Aflexible wrapping has the difliculty that the container is destroyed, inessence, when the package is unwrapped.

However, the cup-lid container described above is not without its owndifficulties. In particular, it is diflicult to arrange for easyreclosing. For reasons of cost, it is preferred that the lid be a flatboard of inexpensive materials which is sealed against the flange. Oncethe lid is pullel free of the flange, the package cannot effectively bereclosed. If the purchaser places the lid back against the flange, thereis nothing to hold it in place and it will fall oif.

One way to avoid the problem is to seal the lid to the cup flange withpressure sensitive adhesive. This type of adhesive remains tacky afterthe package is opened and will reseal the lid to the flange when the lidis replaced. However, there are manufacturing difficulties associatedwith pressure sensitive adhesives because 3,438,483 Patented Apr. 15,1969 of the tendency of a lid coated with this kind of adhesive to stickto everything it touches, Varivous package structures intended toovercome this problem have been considered, many quite ingenous.However, none has been successful in practice because of manufactuingproblems.

The present invention provides an entirely dilferent approach to theproblem. A flat lid is initially sealed to the package by means of anon-reusable adhesive, which will not adhere to the lid when pressedagainst the flange after the package is opened, such as a heat activatedadhesive. The lid is composed of a laminate of metal foil and paper orcardboard. Unlike conventional lids, it extends beyond the flange of thecup at two or more places around the cup, generally at one side thereof.The package is opened in the ordinary way, by breaking the seal on theside where the lid extends beyond the flange. The lid is not removedentirely but a peripheral portion of it is left sealed to the flange onthe side opposite the extending portions. Indicia on the lid indicatethis peripheral portion. The lid is folded back to gain access to thecontents of the cup. When the lid is pressed back against the flange,the consumer folds the lid under the flange at the places where itextends beyond the flange. The foldedunder portion is crimped to theunderside of the flange and holds the lid in place, resistingdisplacement in any direction. The laminated lid has a memorycharacteristic, that is the property of retaining a shape. When crimpedunder the flange, the lid remains in place until the package isreopened.

An important element of the invention is the material used in the lid.This is a laminate of metal foil and paper or paperboard. For purpose ofconvenience, the word paper will be used to include all such materialsmade of fibers, especially of the type made by depositing fibers fromwater slurry onto a screen. Frequently paper is used to refer to suchmaterials up to 0.006 inch thick, while paperboard is frequently used torefer to heavier materials, 0.012 inch thick or more. However, no sucharbitrary limits are intended herein. The paper should be heavy enoughto give body and strength to the laminate, but not so heavy as toprevent manually folding the overhanging portion of the lid to a fairlyneat crease. The weight will depend somewhat on the foil and the kind ofpaper. Its properties can be characterized by reversible bending. If afresh piece of the paper or board about one inch wide and 6 inches longis suspended at its ends, it should bend at most about inch under itsown weight. Generally the paper will be about 5 to 12 mils, preferably 6to 8 mils. Particularly useful materials are bleached sulfite boardhaving a basis weight of to pounds per 3000 square feet or NorthernUnbleached Natural Kraft having a basis weight of 60 to 70 pounds per3000 square feet.

The foil usually will be aluminum, but alloys of aluminum, steel andother metals may be used. The foil should be heavy enough to retain thelid folded but light enough to be easy to fold. Generally it will be 0.4to 1 mil thick. In some cases, there may be a second layer of foil. Forexample, the lid may be a sandwich of two layers of foil on oppositesides of a layer of paper or cardboard. This structure has the advantageof foil exposed to the product in the container and a decorativeexterior foil. In such cases, it is preferred that one layer of foilhave the thickness stated above and that the total thickness not exceed10 mils. It also is possible to include other layers of flexiblematerial. For example, a layer of plastic film such as polyethylene orpolypropylene may be between the paper and one of the layers of foil inthe lastmentioned embodiment.

The invention will be better understood from the following detaileddescription of preferred embodiments, reference being made to thedrawings, in which:

FIGURE 1 is a plan view of a closed rectangular package embodying thepresent invention;

FIGURE 2 is a bottom view of the package of FIG- URE 1;

FIGURE 3 is a cross section of a part of the package of FIGURE 1 takenalong lines 33 of FIGURE 1;

FIGURE 4 is a cross-section of a part of the package of FIGURE 1 takenalong lines 4-4 of FIGURE 1;

FIGURE 5 is a plan view of a circular package according to theinvention;

FIGURE 6 is a bottom view of the package of FIG- URE 5, showing itreclosed;

FIGURE 7 is a cross-section of a part of the package of FIGURE 5 takenalong lines 77 of FIGURE 6;

FIGURE 8 is a cross-section of a part of the package of FIGURE 5 takenalong line 8-8 of FIGURE 6; and

FIGURE 9 is a side elevation of a portion of the package of FIGURE 5viewed along line 9-9 of FIGURE 6.

Referring to FIGURES 1-4, the package illustrated comprises arectangular cup or tray indicated generally by the numeral 1 having arectangular bottom 2, a sidewall 3 extending upwardly and outwardly fromthe bottom 2 and a flange 4 extending laterally outwardly from the topof the sidewall. The corners of the flange are rounded with a relativelylarge radius of curvature 5.

A flat lid 6 is hermetically sealed to the flange 4 around itsperimeter. Along the straight sides of the flange, the lid isapproximately the same width and length as the outer dimensions of theflange. However, at two of the corners at the right side of the package,the lid is rounded to a smaller radius of curvature 7. Consequently, thelid extends beyond the flange at two corners to provide tabs 8 and 9.

As seen in FIGURES 3 and 4, the lid comprises a lower layer of aluminumfoil 12, an intermediate layer of bleached sulfite or natural kraftboard 13, and an upper layer of aluminum foil 14. The thicknesses of thelayers are respectively 0.5, 7 and 0.3 mils.

The lid 6 is initially sealed hermetically to the flange 4. This may beaccomplished by any known means, but a preferred material is a heatactivated adhesive. This is a material which is not tacky at roomtemperature but which becomes tacky when heated. The adhesive layer maybe thermoplastic, that is capable of stiifening on cooling andre-softening and re-stiffening in subsequent heating-cooling cycles.However, it also is possible to use a material which is thermosetting,that is a material which cures on heating and therefore becomesirreversibly stiffened. Numerous materials of this type already areknown to those skilled in the art.

As indicated in FIGURE 1, there are fold lines 10 and 11 printed on thelid to indicate to the consumer where the lid is to be folded. When theconsumer opens the package, the tabs are lifted, the seal is broken, thelid lifted to the lines or indicia 10 and 11, and a part of the contentsare removed. The customer then presses the lid back against the flange.Since some portions of the seal have been broken, the lid no longer canbe secured to the flange in those areas by means of the adhesivepreviously applied. The customer folds the corner tabs 8 and 9 under thecorners of the flange 4 and this prevents the lid from lifting from thecup. Because the lid is constructed of foil and board, the tabs 8 and 9remain folded under the flange 4.

FIGURES 5-9 illustrate another embodiment in which there is a circularcup and a circular lid 21. The cup comprises a circular bottom 22, aside wall 23 extending upwardly and outwardly from the bottom 22 and acircular flange 24 extending laterally outwardly from the sidewall 23.At one side of the cup, two portions of the lid extend beyond the flangeat two points towards an edge 25 which is tangential to the circularflange 24, to form two tabs 26 and 27. The lid is constructed of outerand inner layers of aluminum foil, 33 and 34 and an intermediate layerof board, as in the embodiments in FIG- URES 1-4.

Various other lid-cup arrangements can be conceived wherein the lidextends beyond the flange in two or more distinct positions at one sideof a first center line. It is preferred that where thre are only twotabs they be symmetrically arranged, that is equally spaced from asecond center line perpendicular to said first center line. That is, ifan imaginary center line is drawn from one side of the flange to theother, both of the tabs should be on the same side of it and if a secondimaginary center line is drawn perpendicular to the first, the tabsshould be equally spaced from it. Preferably, the angle between thetabs, that is between lines drawn from the centers of the tabs to thecenter of the lid, is at least about more preferably at least about Onthe other hand, it is preferred that the angle between these tabs notexceed about 110, more preferably 90. Additional tabs may be used, butare in general unnecessary. On the other hand, if only one tab is used,or the tabs are too close together, the lid may curl away from theflange and not adequately reclose the package. In principle, a singleextension can extend continuously around the flange in the above angles,so that, in effect, there are two tabs which are connected togetherrather than two independent tabs. This arrangement is wasteful of lidmaterial and the lid may be harder for the consumer to reclose. However,if used properly, it can effectively provide for reclosing the package.It is especially desirable that there be no tabs on the opposite side ofsaid first center line. In addition to being wasteful of material, theconsumer may be encouraged to lift the lid completely from the flange,which makes it difficult to etfectively reclose the package.

The indicia 10 and 11 set otf a peripheral portion of the lid to be leftsealed to the flange. This portion is on the other side of said firstcenter line and is preferably symmetrical with respect to the secondcenter line. The angle included, i.e. between lines connecting thecenter of the lid with the edges of the peripheral portion preferably isabout 60130.

The distance which the tab extends beyond the flange is not toocritical, although it prferably should not substantially exceed thewidth of the flange nor be substantially less than one-half the width ofthe flange. This assures an ppropriate length of lid material to tuckunder the flange.

Various materials can be used for the cups including synthetic plastics,transparent and opaque, and various metal foils. For example, theinvention is applicable to cups of polystyrene, polyvinyl chloride,relatively rigid aluminum sheet, cardboard and the like, and these maybe coated with various liquid or vapor barrier materials. The flangeshould be at least as stiif as the lid, and preferably should have aneffective flexural modulus at least 1.5 times as great as the flexuralmodulus of the lid so that no difliculty is experienced in folding thetabs. The effective flexural modulus of the flange is the force neededto bend the flange a given angle and will of course depend on theflexural modulus of the cup material, the thickness of the lid and alsothe shape of the cup. Various ribs in the side wall, and also the shapeof the flange itself can reinforce the cup and make it harder to bendthe flange than might be expected from the nature and thickness of thematerial. On the other hand, the flange should not be thicker than aboutMs inch preferably not thicker than inch. If the flange is too thick,the tabs will not grip it as well. In ordinary packages, the flange willbe about 5 to 20 mils thick. In the case of very thick flange materials,an adjustment will have to be made in the width of the extending tabs,such that they will extend a distance equal to the thickness of theflange plus l00% of the width of the flange. However, when the flange isless than inch thick, this correction generally is insignificant and canbe ignored. Normally the flange will be at least about 7 inch wide inthe area where there are lid tabs, preferably A inch or more.

Various other changes can be made in details of construction and mode ofoperation without departing from the scope of the invention, as will beapparent to those skilled in the art.

We claim: 1. A reclosable package comprising a cup having a bottom, aside wall and a flange extending laterally outwardly from said sidewallwith a commodity therein and a lid sealed to said flange and extendingbeyond said flange in at least two places around said flange at one sideof a first center line thereof,

said lid comprising a laminate of a layer of paper and a layer of metalfoil, the portions of said laminate extending beyond said flange beingmanually foldable from a position in the plane of said lid to a positionunder said flange after the package is opened and sufliciently retentiveof the folded configuration to keep said lid on said package duringfurther storage.

2. A reclosable package as set forth in claim 1 in which said lidcomprises a layer of paper and layers of metal foil adhered to oppositesides of said layer of paper.

3. A reclosable package as set forth in claim 2 in which said lidincludes a layer of synthetic plastic between said layer of paper andone of said layers of foil.

4. A reclosable package as set forth in claim 1 in which said lid issealed to said flange with a non-reusable adhesive which will not adheresaid lid to said flange on pressing them together after the package isopened.

5. A reclosable package as set forth in claim 1 including indicia onsaid lid designating a peripheral portion on the other side of saidfirst center line to be left sealed to said flange when the package isopened, said peripheral portion cooperating with the folded underextended portions of said lid when said package is reclosed.

6. A reclosable package comprising a synthetic plastic cup having abottom, a sidewall and a flange about 5 to 20 mils thick and havingportions at least about inch wide extending laterally outwardly from thetop of the sidewall and a generally fiat lid sealed to said flange witha nonreusable adhesive which will not adhere said lid to said flange onpressing them together after the pack- 6 age is opened, said lidextending beyond said flange a distance about 100% of the width of saidflange in at least two places around said flange at one side of a firstcenter line, said places being substantially symmetrical with respect toa second center line perpendicular to said first center line,

the angle between lines connecting said places with the center of saidlid being about 30110,

said lid comprising a laminate which is less stiff than said flange of alayer of paper of about 5 to 12 mils thick and a layer of aluminum foilabout 0.4 to 1 mil thick, the portions of said laminate extending beyondsaid flange being manually foldable under said fiange after the packageis opened and retentive of the folded configuration to keep said flatlid on said package during further storage.

7. A reclosable package as set forth in claim 6 including indicia onsaid lid designating a peripheral portion on the other side of saidfirst center line to be left sealed to said flange when the package isopened, said peripheral portion cooperating with the folded underextended portions of said lid when said package is reclosed.

References Cited UNITED STATES PATENTS 2,990,948 7/ 1961 Zackheim.

3,056,492 10/1962 Campbell.

3,078,986 2/ 1963 Ushkow.

3,079,057 2/ 1963 Colarusso 229-43 XR 3,148,103 9/ 1964 Gallagher.

3,202,271 8/1965 Kirk.

3,272,422 9/1966 Miller 22943 3,335,939 8/ 1967 Robinson 22943 FOREIGNPATENTS 1,278,643 11/1961 France.

OTHER REFERENCES Refrigerating Engineering, February 1954, pp. 45-48.

DAVIS T. MOORHEAD, Primary Examiner.

US. Cl. X.R.

